The 3 and 4 are slightly larger as they were used for iron-type utility clubs in a different model. CRAFTSMAN GOLF iron head cover set, made of black synthetic leather, with each number clearly marked. - Model: CRAFTSMAN GOLF - Head cover numbers: 3, 4, 5, 6, 7, 8, 9, PW, AW, SW, LW - Color: Black - Material: Synthetic leather Thank you for looking.